Background: This dissertation examines conceptual reorganisation in L2 learners by comparing event construal patterns in L1 and L2 discourse. Previous research suggests that the way grammatical aspect is encoded in the speaker's L1 can influence how events are conceptualised in their L2 (von Stutterheim & Carroll 2006). Given the lack of consensus regarding partial (Bylund 2011) versus zero (Schmiedtová et al. 2011) susceptibility to reorganising L1 event construal patterns in L2, the present work contributes to the resonant discussion in this area by investigating the extent to which grammatical aspectual operators influence preverbal message generation (Levelt 1989, Habel & Tappe 1999) in three typologically diverse L1 groups and four L2 groups. The main novel feature of the employed approach is testing L2 learners’ ability to adjust L1 thinking-for-speaking principles (Slobin 1996) in the target language by looking at four conceptualisation processes abreast (i.e. segmentation, selection, structuring and linearization).

Method: Film verbalisations and picture descriptions by Czech, Hungarian and English native speakers; and Czech and Hungarian learners of English at basic and advanced levels were elicited to test (a) whether crosslinguistic event construal contrasts are attributable to the differences in the grammatical means that are available for encoding temporality in particular languages; and (b) whether learners’ degree of susceptibility to reorganising L1 principles for temporal reference in the target language changes as a function of L2 proficiency.

Results: Analyses of L1 speakers’ and L2 learners’ discourse organisation patterns produced three major results. Firstly, preferences in message encoding typical of a given L1 proved closely interrelated with the aspectual operators available in that L1. Secondly, the aspectual system of L1 was found to have an impact on event construal choices in basic and also advanced level learners’ L2 production. And thirdly, consistent patterns across groups remained largely unaffected by changes of modality (speech vs. writing), however, they showed some sensitivity to task type (film retellings vs. picture descriptions).

Conclusions: These findings suggest that the processes of event conceptualisation in L2 largely rest on L1 fundaments, and that persisting L1 principles can lead to significant digressions from target-like performance even in highly advanced learner varieties. Sustained conformity to L1-specific patterns found in all four processes challenges the view that L1 concepts are reorganisable in favour of the L2 concepts (Athanasopoulos & Kasai 2011, Papafragou et al. 2008). Instead, the findings are consistent with studies reporting very limited or no traces of conceptual reorganisation in L2 (Hendriks et al. 2008; von Stutterheim & Lambert 2005).